Theo Walcott says a half-time "rocket" from Arsène Wenger and the desire to avoid making history for the wrong reasons is driving Arsenal towards qualification to the Champions League.

Arsenal wobbled in the latter part of the first half against Wigan Athletic on Tuesday in a game that they had to win to retain control of their destiny. They surrendered the lead and the initiative and, at 1-1, Wenger was furious in the dressing room.

But although they stuttered in the early stages of the second half and could have conceded again, they recovered to win 4-1, with Walcott scoring the decisive second goal – his 21st of the season. The result condemned Wigan to relegation but Arsenal know that victory at Newcastle United on Sunday would ensure that they finish above Tottenham Hotspur and reach the Champions League for the 16th consecutive season.

"We got a rocket," Walcott said. "We'll keep that in the dressing room. But it's great that the manager has that passion and it got a bit more out of the players. We all knew how big it is, not just for the manager but the fans, the players and the club itself. It's massive to be in the Champions League. The manager gave us a kick up the backside. I felt we did show some good play in the first half but we didn't manage to take our chances. Thankfully we did in the second."

Arsenal trailed Tottenham by seven points after they lost the north London derby at White Hart Lane on 3 March but they have since gone unbeaten, seven wins and two draws making them the form team in the division and helping them to reel in their neighbours.

"We just have great experience in knowing what to do when the time is right," Walcott said. "It's funny, it happens every year. We tend to finish very strong. I think it is just because the players want it so much. We need to show that in the mid-season and at the start and we could hopefully be even higher than we are and not have this situation that we are in.

"The Champions League is big for the future of the club and the players. We have been in it for the last 15 years and we don't want to be the players who are not part of that. The Europa League is great and, obviously, Chelsea have made the final. It is great if you get to the final because it is a very tough competition, like the Champions League. But it's all eyes on the Champions League at the moment for us."

Arsenal endured one of the wildest results in recent memory at St James' Park two seasons ago, when they led 4-0 in the 68th minute only to draw 4-4. They also beat Newcastle 7-3 at the Emirates in December.

"I know it was a totally crazy game when we played them at home last year but we are ready for it," Walcott said. "It is a tough game and we cannot underestimate Newcastle. If we show the passion and commitment that we did in the second half against Wigan, we will be OK."